AWS Infrastructure for firepod

Terraform infrastructure for ejc3/firepod CI/CD and development.

Infrastructure

Resource	Type	Purpose
github-runner	c7g.metal spot	GitHub Actions self-hosted runner (ARM64)
firecracker-dev	c7g.metal	Development instance with KVM
jumpbox	t4g.large	Persistent admin host

Auto-scaling Runners

GitHub Actions runners automatically scale based on demand:

• Scale out: Webhook triggers Lambda → launches spot instance when jobs queue
• Scale in: Cleanup Lambda stops idle runners (CPU < 5% for 30 mins)
• Max runners: 3 concurrent (configurable)
• Cost: ~$0.50-0.70/hr per c7g.metal spot

Job queued → Lambda launches spot → Runner picks up job → Idle 30m → Stopped

Commands

# Infrastructure
make init        # Initialize Terraform
make plan        # Preview changes
make apply       # Deploy infrastructure
make output      # Show outputs

# Development instance
make dev-start   # Start firecracker-dev instance
make dev-stop    # Stop instance (preserves disk)
make dev-status  # Show instance status

# GitHub runners
make runners     # List all runner instances

Cost

Resource	Cost	Notes
github-runner	~$0.50/hr	Spot, auto-stops after 30m idle
firecracker-dev	~$2.88/hr	On-demand, auto-stops after 3 days idle
jumpbox	~$0.07/hr	Always on

Idle runners cost $0 - they're stopped automatically.

Files

main.tf              # VPC, subnet, routing
firecracker-dev.tf   # Dev instance + 3-day idle alarm
github-runner.tf     # Base runner + 30m idle alarm
runner-autoscale.tf  # Lambda webhook + cleanup
jumpbox.tf           # Admin host + backups

Setup

1. Clone and initialize:

   git clone https://github.com/ejc3/aws-setup.git
   cd aws-setup
   make init
   make apply

2. GitHub webhook (already configured for ejc3/firepod):

   • URL: https://epteb3h8ia.execute-api.us-west-1.amazonaws.com/webhook
   • Events: workflow_job

3. GitHub PAT stored in SSM:

   aws ssm put-parameter --name /github-runner/pat --value "ghp_xxx" --type SecureString --overwrite

Architecture

┌─────────────────────────────────────────────────────────────┐
│                        VPC (10.0.0.0/16)                    │
│  ┌───────────────────────────────────────────────────────┐  │
│  │                  Subnet A (10.0.1.0/24)               │  │
│  │                                                       │  │
│  │  ┌──────────┐  ┌──────────┐  ┌──────────────────────┐ │  │
│  │  │ jumpbox  │  │ fc-dev   │  │ github-runner (1-3)  │ │  │
│  │  │ t4g.large│  │ c7g.metal│  │ c7g.metal spot       │ │  │
│  │  └──────────┘  └──────────┘  └──────────────────────┘ │  │
│  └───────────────────────────────────────────────────────┘  │
└─────────────────────────────────────────────────────────────┘
                              │
                    ┌─────────┴─────────┐
                    │   API Gateway     │
                    │   (webhook)       │
                    └─────────┬─────────┘
                              │
              ┌───────────────┴───────────────┐
              │                               │
     ┌────────┴────────┐             ┌────────┴────────┐
     │ Lambda: webhook │             │ Lambda: cleanup │
     │ (scale out)     │             │ (scale in)      │
     └─────────────────┘             └─────────────────┘